Look. I'm not that old now -- in my 30s, and I was a young man not that long ago.
I did a lot of dumb stuff as a teenager, or shortly after being one. Thought I was young, precise, with good reflexes, and that I could probably get away with it without hurting anyone -- and thankfully, there I was correct. I did integer multiples of the speed limit across both the US and Canada, several times in both cases.

Thankfully, I didn't manage to hurt myself or anyone else, or damage any property in the process.
I aced physics back then, but didn't really, really understand it and the sort of impact it could have on people's lives until I watched a couple of people die.
Somewhere in my shed, there's a folder with every ticket and written warning I ever received. A lot more things are in that folder than I care to admit to publicly.
I've also lived in about a dozen states, in varying parts of the country, since starting to drive. I've driven about 300,000 mi through nearly all 50 in that time. I'm not bragging, there are plenty of people more experienced than myself on this forum.
One thing I can absolutely say is this:
I never got a warning (written or verbal) for less than 40 in a 35, in town.
On the freeway, of my '70 in a 65' tickets, I was actually doing between 15 and 22 over in every single case, which is the reason I was contacted to begin with. I got a warning written down to 73 because if she'd written me for the actual speed I was doing (87), her boss woulda been pretty pissed at her.
I got lectured in Utah for 68 in a 65 once, but even there, they didn't write me for it.
My experiences with CHP suggest that most don't set their 'care' threshold below about 10-15 over. In 12 years in CA, I only got tagged by CHP once, coincidentally on I-80 East, and I absolutely deserved it.
I commuted about 100-140 mi a day for nearly a decade in the Bay Area after that, and never once got tagged for 5 over by CHP, there are plenty of 15-20 over 'bigger fish' out there.
So, you did one of the following:
1) Followed too close
2) Aggressively changed lanes to maintain that 5 over, drawing the officers attention to you
3) Tried this at 4am when even at 5 over you're the biggest fish out there
OR:
4) You were going a lot faster than 70 in a 65. The same sort of behavior that just got you contacted, AGAIN, by a LEO suggesting you slow down.
So, which was it? I'm guessing you got the break because you more or less passed the attitude test, which is good, but before you complain publicly, again, about being written for 5 over, what else were you doing (speed, or traffic maneuvers)?